As automotive electrical systems become more complex it has been recognized that it would be desirable to provide a junction box or power distribution center with busses therein for connecting a power source to electrical and electronic devices housed by the junction box such as relays and load protective fuses. Such junction boxes should also include provision for electrically connecting the power source and electrical and electronic devices housed by the junction box to electrical wiring harness connectors for supplying power and control signals to various electrical systems of the automobile such as air conditioning systems; fuel supply systems; lighting circuits; instrument panels and to provide signals to engine and auxiliary systems such as anti-skid brake wiring assemblies.
One such power distribution center has an electrical bus and associated printed circuit boards for electrically connecting wiring harnesses to electrical devices carried by the power distribution center. In such centers separate terminals are staked to conductive strips of the printed circuit board to provide an electrical circuit to components such as load protecting fuses. Such terminals require separate soldering steps and the components parts of the printed circuit board are not readily interchanged to adapt the center to different automotive vehicle wiring requirements.
Another approach has been to alternately stack bus bars and insulation boards in a junction box body to provide oppositely facing terminals for connection to electrical devices or wiring harness connectors to complete electrical circuits therebetween. In such cases the bus bars and insulation boards must be separately handled and centered as they are placed in the junction box body.
Yet another approach has been to provide a separate bus bar board and a separate printed circuit board in a junction box body. Relay components are located on the printed circuit board. The junction box body carries separate terminals to connect male blades on the bus bar board to printed conductor strips on the printed circuit board. Such an arrangement requires special tooling for the printed circuit board. Furthermore, separate covers are required to seal the circuit board components and fuse elements which are connected to other parts of the junction box body.
While such prior systems have been suitable for their intended purpose, one problem has been that the separate printed circuit boards, once fabricated, do not provide for adding or removing electrical circuits from the power distribution center.
The aforedescribed prior systems do not provide for centering of circuit components so that a first set of male terminals are easily connected to electrical devices on the junction box body while defining access for aligning a second set of male terminal blades which connect to a female terminator.
An object of the present invention is to provide an electrical power distribution center in which circuit layers are automatically centered as they are assembled in a housing and wherein a first set of male terminal blades on the circuit layers are arranged for connection to electrical devices on one side of the housing and a second set of male terminal blades on the circuit layers are arranged for connection to female terminators.
Another object of the present invention is to eliminate wire splices between wiring harnesses and an electrical power distribution center by providing individually stamped metal circuit components that can be added to or removed from a plurality of circuit layers disposed within a lower housing and wherein the circuit components have oppositely directed male terminal blades thereon that either connect to devices in the electrical power distribution center or to a female connector assembly that supplies power to the electrical assemblies of an automotive vehicle.
Another object of the present invention is to provide such an electrical power distribution center wherein a member is provided on one of a pair of housing components to center the circuit layers with respect to the housing components and to connect the housings together.
Yet another object of the present invention is to provide for such an electrical power distribution center wherein one of the housing components includes a plurality of recesses therein, each receiving a double ended female electrical terminal that is electrically connected to either a male terminal blade of an electrical device or to a male terminal blade formed on an individually stamped replaceable metal circuit component wherein the male terminal blades on the metal circuit components each provide a surface contact with the female electrical terminal which minimizes the force required to connect a plurality of double ended female electrical terminals to the electrical terminations of the circuit layers.
Yet another object of the present invention is to simplify assembly of a multi-layer circuit arrangement in an electrical power distribution center for distributing power between electrical devices wiring harnesses in an automotive electrical system and to do so by the provision of a plurality of circuit layers, each having an electrical insulating board with recesses therein receiving pre-stamped metal circuit components electrically insulated from one another by the electrically insulating board and wherein each pre-stamped metal circuit component is positively located by staking a portion of the board thereagainst.
A further object of the present invention is to provide an electrical power distribution center of the type set forth in the preceding paragraphs wherein the circuit layers are located in juxtaposed relationship and wherein the individual pre-stamped metal circuit components have terminals thereon which are positioned along opposed axes for connection to either electrical devices or to female terminator assemblies for connecting the electrical power distribution center to wiring harnesses in automotive electrical systems.
Still another object of the present invention is to provide such an electrical center wherein one of a pair of housing components has a plurality of members thereon for centering each of the circuit layers with respect to one another and with respect to both the first housing component and a second housing component connected thereto.
Yet another object of the present invention is to provide for such centering by members formed as hollow stems integral of the lower housing component extending therefrom in the direction of the upper housing component and having the outer surface thereof located within centering holes formed in each of the circuit layers.
A further object of the present invention is to provide for such a hollow stem arrangement wherein threaded inserts are provided within each of the centering stems for connection to threaded fasteners at either end thereof, one of which will hold lower and upper housing components together and the other of which will hold a female terminator assembly in place on one of the housings at terminal pads thereon defined by a plurality of male terminals directed from the plurality of circuit layers.
Another object of the present invention is to provide a cover for one of the housings including lo integral position assurance surfaces thereon to locate each of the electrical devices in its interface connected position when the cover is attached to the lower and upper housings.
Yet another feature of the present invention is to provide an opposite opening enclosure on one of the housing components for receiving the end wall of the cover and the other of the housing components so as to define a labyrinth path for restricting flow of ambient material from exteriorly of the electrical center into the interior thereof while permitting expansion of air from the interior of the electrical center to the exterior thereof produced by heating caused by current flow through the pre-stamped metal circuits of the juxtaposed circuit layers.
Other advantages and a more complete understanding of the invention will be more apparent from the succeeding detailed description of the invention taken with the accompanying drawings thereof.